This circuit was found in Radio Electronics from the 90s. It converts capacitance into frequency in order to obtain a proportional voltage that can be measured in a common multimeter.
This circuit was originally designed to power the CB18698's MSX interface, but it is suitable for...
This filter that rejects determines frequency (notch) was found in a Popular Electronics of 1993....
This circuit for measuring bridges was found in the October 1995 issue of Electronics Now...